MAZON CREEK FOSSILSThe Mazon Creek fossils are found in the Upper Carboniferous Francis Creek Shale; the type locality is the Mazon River (or Mazon Creek), a tributary of the Illinois River near Morris, Grundy County, Illinois. The 25 to 30 meters of shale were formed approximately 300 mya, during the Pennsylvanian period. The fossiliferous concretions are usually found within the thickest deposits of Francis Creek. The concretions occur in localized deposits within the silty to sandy mudstones, in the lower four meters of the formation. The paleoecosystem is believed to be a large river delta system, deposited by at least one major river system flowing from the northeast. The sediments are believed to derive from the Appalachian orogeny events. The delta had a tropical climate, a result of the area being within 10° north latitude of the equator during the Pennsylvanian.

The remains of plants and animals were rapidly buried by the sediment deposited in the deltaic system. Bacterial decomposition of the remains produced carbon dioxide that combined with dissolved iron from the groundwater. This process formed siderite in the sediments surrounding the remains, forming detailed casts of their structure. Lithification of the sediments formed protective nodules of ironstone around the now fossilized remains.

The fossiliferous concretions are found in the Mazon River area of Grundy, Will, Kankakee, and Livingston counties. Additional fossils are found in LsSalle County, Illinois; between the Vermilin River and Marseilles, Illinois. The ironstone concretions are recovered from exposures along streams, roadcuts and in active or abandoned coal mine areas.

Mazon Creek flora includes: lycopsids, related to modern club moss, with arborescent forms named Lepidophloios, Sigillaria and Lepidodendron, and herbaceous forms called Lycopodites and Cormophyton; sphenopsids like Calamites a tree-like horsetail relative, with common foliage names of Annularia and Asterophyllites, and a vine-like form called Sphenophyllum; Pteridophyta as marattialean tree ferns and Filicales and Zygopteridales understory ferns, with common foliage names of Pecopteris, Acitheca and Lobatopteris; pteridosperms, also known as seed ferns, an extinct group of plants that grew both as trees and smaller shrubs, with features like pinnated leafs similar to true ferns, but reproduced by seeds instead of spores; they had common foliage names Mariopteris, Alethopteris, Odontopteris, Neuropteris, Laveineopteris and Macroneuropteris; extinct Gymnosperm Cordaites, believed to be closely related to and sharing many features with modern conifers. It has been determined that there are between 250-300 species of Pecopteris.

Fern - Neuropteris sp.

Pennsylvanian Period - 300 myaFrancis Creek ShaleMazon Creek, IllinioisITEM# PLANT-Illinois-0001This is a nice example of the seed fern Neuropteris sp. from the Pennsylvanian of Mazon Creek, Illinois. Neuropteris sp. is a member of the Order Medullosales, Family Medullosaceae.Neuropteris sp. is the name given to the foliage of a seed fern. Seed ferns (Pteridospermales) are an extinct group of gymnosperms. Although their foliage resembled that of modern ferns, they reproduced by means of seeds. Modern ferns reproduce by means of spores.The positive and negative specimens are approximately 2 inches long by 1 inch wide.

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25.00

Fern - Pecopteris Sp.

Pennsylvanian Period - 300 myaMazon Creek, Illinois ITEM# PLANT-Illinois-0002 This is a nice example of the fern Pecopteris sp. from the Pennsylvanian of Mazon Creek, Illinois. Pecopteris sp. is a member of the Order Marattiales, Family Marattiaceae.

Class Marattiopsida is a group of ferns containing a single order, Marattiales, and family, Marattiaceae. Class Marattiopsida diverged from other ferns very early in their evolutionary history and are quite different from many plants familiar to people in temperate zones. Many of them have massive, fleshy rootstocks and the largest known fronds of any fern. The Marattiaceae is one of two groups of ferns traditionally known as eusporangiate fern, meaning that the sporangium is formed from a group of cells versus the leptosporangium in which there is a single initial cell. The positive and negative specimens are approximately 2 7/8 inches long by 2 inches wide.

$50.00
$40.00

Leaf - Lepidophyllum longifolium

Pennsylvanian Period - 300 myaMazon Creek, Illinois ITEM# PLANT-Illinois-0003This is a very large example of the lepidodendroid fossil Lepidophyllum longifolium from the Pennsylvanian of Illinois. Lepidophyllum longifolium is a member of the Order Asterales, Family Asteraceae.Lepidophyllum is a genus of flowering plants in the daisy family. Asteraceae or Compositae (commonly referred to as the aster, daisy, or sunflower family) is an exceedingly large and widespread family of Angiospermae. The group has more than 23,000 currently accepted species, spread across 1,620 genera and 12 subfamilies. In terms of numbers of species. Asteraceae is rivaled only by Orchidaceae. Most members of Asteraceae are herbaceous, but a significant number are also shrubs, vines and trees. The family has a worldwide distribution, and is most common in the arid and semi-arid regions of subtropical and lower temperate latitudes. Asteraceae is an economically important family. Some members provide products including cooking oils, lettuce, sunflower seeds, artichokes, sweetening agents, coffee substitutes and herbal teas. Several genera are popular with the horticultural community, including marigold, pot marigold, (also known as calendula), cone flowers, various daisies, fleabane, chrysanthemums, dahlias, zinnias, and heleniums. Asteraceae are important in herbal medicine, including Grindella, echinacea, yarrow, and many others. A number of species have come to be considered invasive, including, most notably in North America, dandelion, which was originally introduced by European settlers who used the young leaves as a salad green.Lepidolphyllum is a form genus of lepidodendroid fossils based on leaves or parts of leaves that is now recognized to be part of the Lepidodendron tree. The leaves somewhat resemble needles of the modern spruce tree. This very large nodule measures approximately 5 1/2 inches long by 3 1/4 inches wide, by 1 inch thick. Specimen contains both positive and negative plates.